Plastic tote case and method of making same



1968 R. L. BEESLEY ETAL PLASTIC TOTE CASE AND METHOD OF MAKING SAME Original Filed Jan. 6, 1964 2 Shets-Sheet 1 m, mi n HM ii Aobr/ L. flees/e John W M/ghfon BY Rudolph Maff/w'as mwxm TNVENTORS. I

Jan. 9; 1968 R. L. BEESLEY E'II'AL 3,362,576

PLASTIC TOTE CASE AND METHOD OF MAKING SAME Original Filed Jan. 6, 1964 United States Patent PLASTIC TOTE CASE AND METHOD OF MAKING SAME Robert L. Beesley, Saginaw, John W. Mighton, Midland, and Rudolph H. Matthias, Saginaw, Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware Original application Jan. 6, 1964, Ser. No. 335,739. D1-

vided and this application Feb. 23, 1966, Ser. No.

4 Claims. (Cl. 220-97) ABSTRACT OF THE DISCLOSURE A plastic tote casefor milk cartons and the like having a bottom wall and an upwardly extending sidewall, a stacking shoulder extending horizontally inwardly of the lower end of the sidewall to and exposing the lower peripheral edge of the bottom wall, and protuberances extending outwardly ofthe lower edge of the bottom wall. Beneficially, the protuberances extend outwardly a sufficient distance so as to snugly engage the inner surface of the top portion of the sidewall of a like tote case stacked directly therebelow to give additional rigidity to the stacked cases.

This application is a division of application Ser. No. 335,739, filed Jan. 6, 1964.

This invention relates generally to tote cases and, more particularly, relates to tote cases particularly suited for handling products such as paperboard and plastic liquid containing packages, and to the method of making such cases.

Prior plastic tote cases fail to provide satisfactory stacking of a plurality of such cases as well as fail to provide a case bottom structure having adequate drainage facilities and yet being of suflicient strength to endure harsh treatment.

Accordingly, it is an object of the present invention to provide an improved plastic tote case for handling and storing containers.

Another object of the present invention is to provide an improved plastic tote case which combines the advantageous features of adequate drainage and bottom strength.

Yet another object of the present invention is to provide a plastic tote case having greatly improved stacking rigidity.

Another object of the present invention is to provide a tote case having a novel internal corner construction designed for maximum strength and substantial elimination of interference with square containers being packed in the case.

Yet another object of the present invention is to provide a bottom structure for a tote case which is of such a configuration that when it is formed, uniform controlled material distribution in parts can be had even though it be of a generally square or other rectangular configuration.

Briefly then, the present invention thus resides in an improved plastic tote case having all the advantages of the prior cases plus improved stacking characteristics due to an offset shoulder and outwardly extending protuberances. Recessed internal corners are provided in the case which substantially prevent corner fitting of rectangularly shaped cartons. Also comprehended is an improved bottom construction which provides adequate drainage while retaining substantial strength. Co-extensive with the above is a method for forming the bottom construction which method provides for a uniform control of material distribution in the molding thereof.

Yet additional objects and advantages of the present invention, and its numerous cognate benefits and features are even more apparent and manifest in and by the ensuing description and specification taken in conjunction with the accompanying drawing in which, wheresoever possible, like charcaters of reference designate corresponding material and parts throughout the several views thereof, in which:

FIGURE 1 is a side View of a tote case constructed according to the principles of the subject invention, all sides being substantially alike;

FIGURE 2 is a top plan View thereof;

FIGURE 3 is a bottom view thereof;

FIGURE 4 is an enlarged fragmentary section of two tote cases stacked together, the bottom of an upper tote case stacked upon the top of the lower tote case; and

FIGURE 5 is a bottom plan view of a modified form of tote case having an elongated rather than a square bottom configuration.

Tote case or container 10 is illustrated in FIGURES 1-4 as having a substantially square bottom 11 with side walls 12 extending upwardly therefrom. It is best molded from a lightweight plastic material such as high impact polystyrene or rigid polyethylene, or of other plastic materials having like characteristics. The four side walls 12 of container 10 preferably have a corrugated cross-section formed by undulations 14 to provide increased stacking rigidity, improved control of warpage, minimal moisture condensation, and faster cool-down of the container and contents. Such undulations '14 have been found especially useful in thin Walled plastic cases. Corners 15, formed by adjacent side walls 12, are recessed so as to prevent a tight mated fit with corners of cartons, or the like, contained within tote case 10.

It is noted that each side wall 12 has hand opening 16 with a lip or raised flange 18 around the periphery thereof to provide a reinforced grip. Formed around the upper periphery of each side Wall is a thickened portion 20 which concludes in downwardly extending corner portions 22, the latter containing holes 24 which can be engaged by hooks or the like when the cases are moved by heavy equipment.

The lower end of each side wall 12 merges into bottom 28 by way of a recessed stacking shoulder portion 26 which gives a generally flat vertical surface or lower peripheral bottom edge 30 with bumps or rounded tapered prot-urberances 32 located in spaced relationship therealong, as best seen in FIGS. 1 and 4. Protuberances 32 act as spacers juxtapositionable with the inner surface 34 about the top of a stacked tote case of a similar configuration. Preferably, protuberances 32 extend from the surface 30 a distance so as to snugly engage inner surface 34 to give added rigidity to the stacked cases. It can readily be seen that shoulder 26 rests upon the upper peripheral edge 36 of the case therebelow.

FIGURE 3 especially shows that the bottom 18 of tote case 10 is formed about a pluraltiy of cut-outs 38 which provide the improved drainage capabilities of the case, both when it holds containers and when it is in a plant, such as a dairy, being cleaned. The cut-outs 38 are defined by crossed planar portion 40 which is in turn reinforced downwardly extending ridges 42 along approximately all of its surface. The T-shaped cross section construction formed by planar portion 40 and downwardly extending rib 42 give improved rigidity. Cut-outs 38 are generally in the form of parallograms except about the periphery of the bottom where they are in the form of triangles approximately one-half the size of the parallelograms. The crosses formed by planar portion 40 comprise at least linear diagonals extending generally across said bottom wall between opposite corners thereof.

In forming such a container and its bottom configuration, plastic material is injected into a mold in equal di- 3 rections from the center of the bottom through a gate (not shown). The location of the gate is defined in FIG- URE 3 by central aperture 44 which is surrounded by thickened peripheral flange 46. When a case is injection molded, plastic flows from the center portion, under pressure, in a flow pattern substantially as defined by surfaces 40 and ribs 42., which pattern makes the distance from the orifice of the gate to peripheral points around the sides, such as 48, 50, 52, etc., the same. Thus, the distance through which the material must flow, i.e. from the gate to the corners or the side walls, is the same in every instance. Such uniform controlled material distribution in molded cases having square or rectangular bases eliminates the prior problems caused by warping, poor weld lines, packing stress, and all the other inherent characteristics in prior art designs.

That an elongated rectangular base for a tote case can likewise have uniform material distribution when molded through a central gate is illustrated by FIGURE 5. For example, here the flow distance from central aperture 54 of case 56 to the corners, such as corner 58, is the same as the flow distance to any point on the sides, such as to points 60 or 62, the distance being defined by ribs 64. Ribs 64 in this instance define cut-outs 66 in the shape of parallelograms about the center and triangles about the periphery of the bottom.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

Accordingly, what is claimed as new is:

1. A tote case comprising a box-like structure having a bottom wall, upwardly extending sidewalls surrounding said bottom wall, a stacking shoulder extending generally horizontally inwardly of said sidewalls and exposing the lower peripheral edge of said bottom Wall, said lower peripheral edge of the bottom wall being dimensionally less than the upper inner extent of said sidewalls, protuberances extending outwardly of said lower peripheral edge of the bottom wall, said protuberances acting as spacers juxtapositional with the upper inner extent of the sidewalls of a like tote case stacked therebelow.

2. A tote case comprising a box-like structure having a bottom wall, upwardly extending sidewalls surrounding said bottom wall, a stacking shoulder extending generally horizontally inwardly of said sidewall and exposing the lower peripheral edge of said bottom wall, said lower peripherel edge of the bottom wall being dimensionally less than the upper inner extent of said sidewalls, protuberances extending outwardly of the lower peripheral edge of said bottom wall, said protuberances being tapered upwardly and outwardly and extending a distance at their upper portion sufficient to snugly engage the inner surface of the top portion of the sidewalls of a like tote case stacked directly therebelow.

3. A tote case comprising a box-like structure having a bottom wall, upwardly extending sidewalls surrounding said bottom wall, a stacking shoulder extending generally horizontally inwardly of said sidewall and exposing the lower peripheral edge of said bottom wall, said lower peripheral edge of the bottom wall being dimensionally less than the upper inner extent of said sidewall, protuberances extending outwardly of the lower peripheral edge of said bottom wall, the lateral extent of said bottom wall with protuberances being approximately the same as the lateral extent between the inside surface of opposite sidewalls about the top of said case.

4. A tote case comprising a box-like structure having a bottom wall, upwardly extending sidewalls surrounding said bottom wall, a stacking shoulder extending generally horizontally inwardly of said sidewall and exposing the lower peripheral edge of said bottom wall, said lower peripheral edge of the bottom wall being dimensionally less than the upper extent of said sidewalls, protuberances extending outwardly of the lower peripheral edge of said bottom wall, said bottom wall comprising a planar portion having a plurality of cutouts therein, said cut-outs defining triangles about the periphery of said bottom wall and parallelograms approximately twice the area of said triangles about the rest of said bottom wall, the planar portion comprising at least linear diagonals extending generally across said bottom wall between opposite corners thereof, said diagonals at their crossing defining at least one aperture, and reinforcing rib means extending downwardly from said planar portion.

References Cited UNITED STATES PATENTS 3,002,650 10/1961 Lovell 22097 3,005,572 10/ 1961 Gustafson 22072 3,055,531 9/1962 De Chelbor 22021 3,186,586 6/1965 Box 22097 FOREIGN PATENTS 1,271,931 8/1961 France.

822,3 O9 10/ 1959 Great Britain.

956,026 1/ 1957 Germany.

THERON E. CONDON, Primary Examiner,

E, Assistqnt Examiner, 

